1. Field of the Invention
The present invention relates to an information processing apparatus, an information capturing apparatus, an information integration apparatus, and an object detector, all preferably being installed in a vehicle, as well as to an information processing method.
2. Description of the Related Art
A vehicle typified by a car is equipped with sensors of many types. The respective sensors capture information pertaining to circumstances surrounding a vehicle, in different manners. Sensors are roughly classified into a monitor for monitoring the circumstances of a vehicle and information capturing apparatus for capturing information pertaining to travel of vehicle. Monitors are typified by radar, sonar, or an object recognition apparatus using an image processing technique. Information capturing apparatus are typified by a navigation system and an inter-vehicle communication system. Pieces of information pertaining to the circumstances surrounding a vehicle captured by the sensors of several types installed in a single vehicle are integrated by an information integration apparatus. A controller performs an adaptive task pertaining to vehicle control, through use of the result of integration of information pieces.
Japanese Patent Application Laid-Open No. 332810/1998 describes a radar including a plurality of antenna/transceiver sections. Each of the antenna/transceiver sections of the radar receives an electromagnetic wave reflected from an object of measurement through use of an aerial. Each of the antenna/transceiver sections determines an intensity level of an object on the basis of the power of a received electromagnetic wave with reference to an elevation angle of the aerial. The intensity levels of the object determined by all the antenna/transceiver sections are integrated. Intensity levels of the object within a rectangular area including border lines among overlapping maximum observation ranges of respective antenna/transceiver sections are two-dimensionally averaged and smoothed. Weights are assigned to a plurality of meshes within each rectangular area during a smoothing operation. Thus, the thus-integrated intensity level of the object is displayed.
Formats of the information pieces captured by the sensors of various types installed in the vehicle differ from one another, and in many cases parameters of respective information pieces differ from one another. For example, a parameter of the information pertaining to the surroundings of a vehicle captured by the monitor may be a relative distance between the vehicle and an object, a relative speed of the object, or the presence/absence of an object at a predetermined location. Information pieces which are objects of integration and are delivered to the information integration apparatus from sensors are not uniform with regard to content. For example, information about objects which are present around the vehicle and information about the geometry of a road on which the vehicle is now driving are delivered to the information integration apparatus. In order to produce information available for a vehicle controller, the information integration apparatus of the conventional art integrates the information pieces of different contents, such that information pieces of high reliability level among the thus-captured information pieces are combined together. Japanese Patent Application Laid-Open NO. 332810/1998 states only the method of integrating information pieces of identical formats and fails to state a method of integrating information pieces of different formats.
In the information integration apparatus of the conventional art, combination of sensors changes in accordance with adaptive tasks of the vehicle controller. Even in the case of a single adaptive task, a plurality of combinations of sensors are available. The information integration method must be defined in accordance with a combination of sensors which output information pieces to be integrated. In connection with an information integration method designed for a certain combination of sensors, branch steps are set according to the information output from each of the sensors combined. A processing routine is limited for the certain combination. If the combination of sensors is changed, application of the information integration method to a modified combination of sensors is difficult. For this reason, the information integration method must be changed in agreement with a modification to the combination of sensors whose outputs are objects of integration. Particularly, in a case where parameters of information pieces which are objects of integration are variable or where the structures of information pieces differ, processing operations of information integration apparatus must be greatly changed even when one of the sensors of various types is replaced.
For these reasons, the manufacturer of information integration apparatus must prepare information integration apparatus of different structures in number equal to the combinations of sensors and the combinations of adaptive tasks of the controller. Each time a new combination between the combination of sensors and an adaptive task of the controller is conceived, the design of the information integration apparatus must be changed fundamentally. As a result, the load imposed at the time of designing of the information integration apparatus is increased, and costs for manufacturing the information integration apparatus is increased. Each time the combination of sensors and the combination of adaptive tasks of a controller are changed, the information integration apparatus must be changed, and hence load imposed on manufacture of a vehicle is also increased.
The information integration method must be defined in accordance with the traveling state of a vehicle, weather conditions, the geometry of a road, and the state of provision of information. Hence, the information integration method must be changed in agreement with the traveling state of a vehicle and weather conditions. Since a processing routine of the information integration method is difficult to change, changing of the information integration method in accordance with the traveling state is difficult.